Field of the Invention
The present invention relates to an imprint apparatus, an imprint system, and a method of manufacturing an article.
Description of the Related Art
An imprint technique is a technique of enabling the transfer of a nano-scale fine pattern and has been proposed by Japanese Patent Laid-Open No. 2010-98310 as a mass-production nanolithography technique for devices such as semiconductor devices and magnetic storage media. An imprint apparatus using an imprint technique cures a resin (imprint material) on a substrate while a mold on which a pattern is formed is in contact with the resin, and forms the pattern on the substrate by releasing the mold from the cured resin. In this case, as a resin curing method, a photo-curing method is generally used, which cures a resin by irradiation with light such as ultraviolet light.
When using an imprint apparatus, in order to maintain the performance of a device, it is necessary to accurately transfer a pattern on a mold onto a pattern (shot region) on a substrate. In this case, in general, the shape of the pattern on the mold is matched with the shape of the pattern on the substrate. For example, a correction mechanism which deforms the pattern on the mold by pushing and pulling its peripheral portion, that is, a correction mechanism which corrects the shape of a pattern is proposed in Japanese Patent Laid-Open No. 2008-504141.
In addition, the imprint apparatus generally uses die-by-die alignment as an alignment scheme between a mold and a substrate. Die-by-die alignment is an alignment scheme of correcting the displacement between a mold and a substrate by detecting marks provided on the mold and marks provided on the substrate for each shot region on the substrate.
A conventional imprint apparatus generally corrects the shape of a pattern on a mold by using the mark detection results obtained in die-by-die alignment. However, it is necessary to detect many marks to obtain the shape of a shot region on a substrate. It therefore requires much time for detection, leading to a reduction in the productivity of the imprint apparatus. In addition, the response speed of the correction mechanism for correcting the shape of a pattern is low, and hence there is a possibility that the shape of a mold cannot be completely corrected during die-by-die alignment.
In addition, there has been proposed a technique of obtaining the shape of a shot region of a substrate in advance. In this technique, the shape of a shot region within a substrate is represented by a fixed value (that is, the shape of each shot region is fixed to one shape). Alternatively, a shape at each shot position on each substrate is represented by a fixed value. This makes it impossible to cope with variations in shape among the respective shot regions within a substrate or among substrates, resulting in inability to sufficiently correct the shape of a pattern on a mold. Recently, with advances in microfabrication of devices, high overlay accuracy is required. As a result, such problems become especially conspicuous.